Electrostatic protective element and electronic device

Abstract

The present technique relates to an electrostatic protective element that enables protective performance with respect to static electricity to be improved and to an electronic device. An electrostatic protective element includes: a first impurity region of a first conductivity type which is formed on the predetermined surface side of a semiconductor substrate; a second impurity region of a second conductivity type which is formed on the predetermined surface side of the semiconductor substrate so as to form a clearance in a horizontal direction with respect to the first impurity region; a collector contact which is formed on the predetermined surface side in the first impurity region, which has a higher concentration than the first impurity region, and which is an impurity region of the first conductivity type; a base contact which is formed on the predetermined surface side in the second impurity region, which has a higher concentration than the second impurity region, and which is an impurity region of the second conductivity type; and an emitter contact which is formed on the predetermined surface side in the second impurity region at a position that is closer to the collector contact than the base contact, which has a higher concentration than the second impurity region, and which is an impurity region of the first conductivity type. The present technique can be applied to, for example, an electronic device.

The invention claimed is: 
     
       1. An electrostatic protective element, comprising:
 a first impurity region of a first conductivity type, wherein the first impurity region is on a specific surface side of a semiconductor substrate; 
 a second impurity region of a second conductivity type, wherein the second impurity region is on the specific surface side of the semiconductor substrate so as to form a clearance in a horizontal direction with respect to the first impurity region; 
 a collector contact on the specific surface side in the first impurity region, 
 wherein the collector contact has a higher concentration than the first impurity region, and the collector contact is an impurity region of the first conductivity type; 
 a base contact on the specific surface side in the second impurity region, wherein 
 the base contact has a higher concentration than the second impurity region, and 
 the base contact is an impurity region of the second conductivity type; 
 an emitter contact on the specific surface side in the second impurity region at a position that is closer to the collector contact than is the base contact, wherein 
 the emitter contact has a higher concentration than the second impurity region, and 
 the emitter contact is an impurity region of the first conductivity type; 
 a fifth impurity region which at least covers a bottom surface of the first impurity region and a bottom surface of the second impurity region at a position that is deeper than the first impurity region and the second impurity region of the semiconductor substrate, wherein the fifth impurity region has a lower concentration than the first impurity region and the second impurity region; and 
 a sixth impurity region of the second conductivity type, wherein 
 the sixth impurity region is between the collector contact and the fifth impurity region, and 
 the sixth impurity region covers at least a part of a bottom surface of the collector contact and has a lower concentration than the collector contact. 
 
     
     
       2. The electrostatic protective element according to  claim 1 , further comprising a third impurity region of the second conductivity type, wherein
 the third impurity region is at a position that is closer to the collector contact than is the emitter contact on the specific surface side in the second impurity region, and 
 the third impurity region has a higher concentration than the second impurity region. 
 
     
     
       3. The electrostatic protective element according to  claim 2 , further comprising a fourth impurity region of the first conductivity type, wherein
 the fourth impurity region is at a position that is closer to the emitter contact than is the collector contact on the specific surface side in the first impurity region, and 
 the fourth impurity region has a higher concentration than the first impurity region. 
 
     
     
       4. The electrostatic protective element according to  claim 2 , wherein a depth of the third impurity region is approximately same as a depth of the emitter contact. 
     
     
       5. The electrostatic protective element according to  claim 2 , wherein the impurity concentration of the third impurity region is equal to or higher than the impurity concentration of the emitter contact. 
     
     
       6. The electrostatic protective element according to  claim 1 , further comprising a fourth impurity region of the first conductivity type, wherein
 the fourth impurity region is at a position that is closer to the emitter contact than is the collector contact on the specific surface side of the first impurity region, and 
 the fourth impurity region has a higher concentration than the first impurity region. 
 
     
     
       7. The electrostatic protective element according to  claim 6 , wherein a depth of the fourth impurity region is approximately same as a depth of the collector contact. 
     
     
       8. The electrostatic protective element according to  claim 6 , wherein the impurity concentration of the fourth impurity region is equal to or higher than the impurity concentration of the collector contact. 
     
     
       9. The electrostatic protective element according to  claim 6 , wherein a position of the collector contact is separated from the position of the fourth impurity region in the horizontal direction. 
     
     
       10. The electrostatic protective element according to  claim 1 , wherein a depth of the first impurity region is approximately same as a depth of the second impurity region. 
     
     
       11. An electronic device comprising
 a semiconductor apparatus that comprises an electrostatic protective element, wherein the electrostatic protective element includes: 
 a first impurity region of a first conductivity type, wherein the first impurity region is on a specific surface side of a semiconductor substrate; 
 a second impurity region of a second conductivity type, wherein the second impurity region is on the specific surface side of the semiconductor substrate so as to form a clearance in a horizontal direction with respect to the first impurity region; 
 a collector contact on the specific surface side in the first impurity region, wherein 
 the collector contact has a higher concentration than the first impurity region, and 
 the collector contact is an impurity region of the first conductivity type; 
 a base contact on the specific surface side in the second impurity region, wherein 
 the base contact has a higher concentration than the second impurity region, and 
 the base contact is an impurity region of the second conductivity type; 
 an emitter contact on the specific surface side in the second impurity region at a position that is closer to the collector contact than is the base contact, wherein 
 the emitter contact has a higher concentration than the second impurity region, and 
 the emitter contact is an impurity region of the first conductivity type; 
 a third impurity region which at least covers a bottom surface of the first impurity region and a bottom surface of the second impurity region at a position that is deeper than the first impurity region and the second impurity region of the semiconductor substrate, wherein the third impurity region has a lower concentration than the first impurity region and the second impurity region; and 
 a fourth impurity region of the second conductivity type, wherein 
 the fourth impurity region is between the collector contact and the third impurity region, and 
 the fourth impurity region covers at least a part of a bottom surface of the collector contact and has a lower concentration than the collector contact.